Divide. Write your answer in simplest form. $ \dfrac{9}{2} \div \dfrac{1}{4} = {?} $
Solution: Dividing by a fraction is the same as multiplying by the reciprocal of the fraction. The reciprocal of $\dfrac{1}{4}$ is $\dfrac{4}{1}$. Therefore: $ \dfrac{9}{2} \div \dfrac{1}{4} = \dfrac{9}{2} \times \dfrac{4}{1} $ $ \phantom{\dfrac{9}{2} \div \dfrac{1}{4}} = \dfrac{9 \times 4}{2 \times 1} $ $ \phantom{\dfrac{9}{2} \div \dfrac{1}{4}} = \dfrac{36}{2} $ Simplify: $ 18$